Blast-induced traumatic brain injury of goats in confined space

Abstract

Objective:To study blast-induced traumatic brain injury (bTBI) characteristics in confined space.Methods:The goats were placed at the column-like buildings with trinitrotoluene (TNT) as the source of the blast wave. The pressure was recorded at 2–8 m from the explosion center. The systemic physiology, electroencephalogram (EEG), serum level of S-100beta, and neuron specific enolase (NSE) were determined pre and post the exposure. Neuroanatomy and neuropathology were observed 4 hours after the exposure.Results:The blast waveform was composed of two peaks from the incident and reflection wave with a range of pressure–duration from 555/913 kPa–0·663 milliseconds at 2 m to 45/71 kPa–2·7/2·367 milliseconds at 8 m. At 2 m, the goats experienced brain depression while the heart rate and respiratory rate concomitantly increased with bloody foam fluid emission from the nose and the mouth. Of the goats, 88·89% were burned. The distinctive gross neuroanatomical changes were congestive expansion of surface vessels on the hemisphere cerebellum and brainstem along with subarachnoid hemorrhage on the frontal lobe, mesencephalon, and brainstem. Subarachnoid hemorrhage, enlarged perivascular space, vascular dilatation and congestion, and parenchymal hemorrhagic could be easily observed microscopically. High amplitude and low frequency of waveforms appeared in the EEG. The serum concentration of S-100beta and NSE were elevated. Although these pathophysiological changes diminished with increasing distance from the explosive center, these changes existed for the 8 m subjects.Conclusions:Blast-induced traumatic brain injury can be induced by a complex blast wave with a pressure and duration of 45/71 kPa and 2·7/2·367 milliseconds. Its severity is related to the features and waveforms of the blast.